Multiple crown size variables of the upper incisors in patients with supernumerary teeth compared with controls

Aims: As part of ongoing studies of the aetiology of dental anomalies the aims of this study were to identify multiple components of tooth size of the upper permanent incisors in 34 patients with supernumerary teeth and to compare them with those in a control group to determine whether the presence of a supernumerary tooth has a local effect on the size of the surrounding dentition. Methods and results: The labial and occlusal aspects of the clinical crowns of the upper permanent central and lateral incisors on the study models of 74 subjects were digitally imaged and measured using an image analysis system and automated macro (34 patients with supernumerary in the upper incisor region: 17 males and 17 females and 40 controls: 20 males and 20 females). The macro-defined 17 variables from each view. From the labial view these were: the mesio-distal and occluso-gingival length and additional measurements along 25 and 75% of the mesio-distal line and at 25, 50 and 75% along the occluso-gingival line such that all these sub-divisions extended to the periphery of the tooth. From the occlusal view these were: the mesio-distal and labio-lingual lengths, and additional variables that sub-divided the mesio-distal again at 25 and 75% along the length and at 25, 50 and 75% along the labio-lingual dimension. Principal component analysis (PCA) was used to identify the key factors with the most random variability. Comparisons were then carried out between the supernumerary cases and control group using 2-way ANOVA. Seven factors of tooth size for the upper central incisors and eight factors for the upper lateral incisors were extracted. Most of these variables were found to be larger in the supernumerary group than in the control. Statistically significant differences were found for 5 out of 7 and 4 out of 8 for the upper central and lateral incisors respectively. Conclusions: A number of factors of tooth size were identified and found to be larger in the supernumerary group compared to the control (7 for upper central and 8 for upper lateral incisors); the majority reached the 0.05 significance level. Tooth crown size of the upper central incisor was affected more than that of the upper lateral incisor, supporting a local field effect. (C) 2008 Elsevier Ltd. All rights reserved

Channeling by Proximity: The Catalytic Advantages of Active Site Colocalization Using Brownian Dynamics

Nature often colocalizes successive steps in a metabolic pathway. Such organization is predicted to increase the effective concentration of pathway intermediates near their recipient active sites and to enhance catalytic efficiency. Here, the pathway of a two-step reaction is modeled using a simple spherical approximation for the enzymes and substrate particles. Brownian dynamics are used to simulate the trajectory of a substrate particle as it diffuses between the active site zones of two different enzyme spheres. The results approximate distances for the most effective reaction pathways, indicating that the most effective reaction pathway is one in which the active sites are closely aligned. However, when the active sites are too close, the ability of the substrate to react with the first enzyme was hindered, suggesting that even the most efficient orientations can be improved for a system that is allowed to rotate or change orientation to optimize the likelihood of reaction at both sites

Safeguarding children in dentistry: 1. Child protection training, experience and practice of dental professionals with an interest in paediatric dentistry

* Few dental professionals with child protection training have experience of making referrals. * There is a wide gap in practice between recognising signs of child abuse and neglect and responding effectively. * This may indicate missed opportunities to save children from continuing abuse. * There is a need for improved child protection information, support and training for dental professionals. Abstract Following several highly publicised inquiries into the deaths of children from abuse and neglect, there has been much recent interest in the role and responsibility of all health professionals to protect children at risk of maltreatment. The findings of a postal questionnaire, sent in March 2005 to 789 dentists and dental care professionals with an interest in paediatric dentistry working in varied settings in the UK, are presented in a two-part report and discussed in the context of current multi-agency good practice in safeguarding and promoting the welfare of children. This first part explores reported child protection training, experience and practice. There was a significant gap between recognising signs of abuse and responding effectively: 67% of respondents had suspected abuse or neglect of a child patient at some time in their career but only 29% had ever made a child protection referral. The dental profession is alerted to the need to ensure necessary appropriate action to safeguard children is always taken when child abuse or neglect are suspected

Capturing the essence of folding and functions of biomolecules using Coarse-Grained Models

The distances over which biological molecules and their complexes can function range from a few nanometres, in the case of folded structures, to millimetres, for example during chromosome organization. Describing phenomena that cover such diverse length, and also time scales, requires models that capture the underlying physics for the particular length scale of interest. Theoretical ideas, in particular, concepts from polymer physics, have guided the development of coarse-grained models to study folding of DNA, RNA, and proteins. More recently, such models and their variants have been applied to the functions of biological nanomachines. Simulations using coarse-grained models are now poised to address a wide range of problems in biology.Comment: 37 pages, 8 figure

Determinants of children’s oral health-related quality of life following aesthetic treatment of enamel opacities

Objectives To identify clinical and psychosocial predictors of oral health-related quality of life (OHRQoL) in children with molar incisor hypomineralisation (MIH) following aesthetic treatment of incisor opacities. Methods Participants were 7- to 16-year-old children referred to a UK Dental Hospital for management of incisor opacities. Prior to treatment (To), participants completed validated questionnaires to assess OHRQoL and overall health status (C−OHIP-SF19), and self-concept (Harter’s Self-Perception Profile for Children [SPPC]). Interventions for MIH included microabrasion, resin infiltration, tooth whitening or composite resin restoration. Children were reviewed after six months (T1) when they re-completed the C−OHIP-SF19 and SPPC questionnaires. The relationships of predictors with improvement of children’s OHRQoL (T1-To) and children’s overall health status at T1 were assessed using linear and ordinal logistic regression respectively, guided by the Wilson and Cleary’s theoretical model. Results Of 103 participants, 86 were reviewed at T1 (83.5 % completion rate). Their mean age was 11-years (range = 7−16) and 60 % were female. Total and domain OHRQoL scores significantly increased (improved OHRQoL) following MIH treatment. There was a significant positive change in SPPC physical appearance subscale score between To and T1. A higher number of anterior teeth requiring aesthetic treatment were associated with poor improvement of socio-emotional wellbeing at T1 (Coef =-0.43). Higher self-concept at To was associated with greater improvement of socio-emotional wellbeing at T1 (ß = 3.44). Greater orthodontic treatment need (i.e. higher IOTN-AC score) at T0 was linked to worse overall oral health at T1 (OR = 0.43). Conclusions Psychosocial factors and dental clinical characteristics were associated with change in children’s OHRQoL following minimal interventions for incisor opacities. Clinical significance MIH is a common condition and clinicians should be aware of the negative impacts some children experience, particularly those with multiple anterior opacities, poor tooth alignment and low self-concept. However, simple, minimally invasive treatments can provide good clinical and psychosocial outcomes and should be offered to children reporting negative effects

Change in Oral Health-Related Quality of Life Following Minimally Invasive Aesthetic Treatment for Children with Molar Incisor Hypomineralisation: A Prospective Study

Molar incisor hypomineralisation (MIH) is a common enamel condition, presenting with incisor opacities, which may be of psychosocial concern to children. This clinical study sought to determine whether minimally invasive treatment, aiming to improve incisor aesthetics, would also improve children's oral health-related quality of life (OHRQoL). 111 MIH patients, aged 7⁻16 years, referred to a UK Dental Hospital, were invited to complete the Child Oral Health Impact Profile (C-OHIP-SF19) prior to any intervention (T₀) and again at one-month following the intervention (T₁) for MIH. Treatment regimens included one or more of the following: Microabrasion; resin infiltration; tooth whitening; resin composite restoration. Data were obtained for 93 children with a mean age of 11 years. Mean total C-OHIP-SF19 score at T₀ was 47.00 (SD = 9.29; range = 0⁻76) and this increased significantly at T₁ to 58.24 (SD = 9.42; range = 0⁻76; p < 0.001, paired t-test), indicating a marked improvement in self-reported OHRQoL. There were no statistically significant differences according to gender. This is the first study to show that simple, minimally invasive dental treatment, to reduce the visibility of enamel opacities, in MIH, can have a positive impact on children's wellbeing

Participation in an Advanced Anatomy Capstone Project Facilitates Student Involvement in the Development of an Instructional Tool for Novel Dissection

Introduction. Student-driven design of instructional tools within basic sciences curricula in general, and in anatomy in particular,has been shown to be both a positive educational experience for the student developers and a viable way to create quality materials for future courses. We present here a description of a student collaboration arising from participation in an advanced anatomy capstone research project, resulting in the creation of a new dissection protocol for the thoracolumbar junction dorsal primary rami and their branches. Materials and Methods. This project was initiated by two third-year doctor of physical therapy (DPT)students and involved participation from faculty and other DPT students of varying experience levels, in order to pilot and refine the tool over a two-year period. We describe the process by which the tool was developed, from the genesis of the original idea through the piloting stage. Results and Discussion. This collaboration resulted in a new instructional tool to be launched within our first-year DPT gross anatomy labs in 2022. Evaluation of the project through qualitative interviews demonstrated the learning impact on student participants. Conclusions. The success of this project shows the potential for students to be meaningfully involved in instructional tool design. ,e complete dissection guide, along with photos, is included and will be of particular relevance for medical and health science educators with an interest in orthopedics, neurosurgery, pain management, or physical therapy

Influence of Nanoparticle Size and Shape on Oligomer Formation of an Amyloidogenic Peptide

Understanding the influence of macromolecular crowding and nanoparticles on the formation of in-register $\beta$-sheets, the primary structural component of amyloid fibrils, is a first step towards describing \emph{in vivo} protein aggregation and interactions between synthetic materials and proteins. Using all atom molecular simulations in implicit solvent we illustrate the effects of nanoparticle size, shape, and volume fraction on oligomer formation of an amyloidogenic peptide from the transthyretin protein. Surprisingly, we find that inert spherical crowding particles destabilize in-register $\beta$-sheets formed by dimers while stabilizing $\beta$-sheets comprised of trimers and tetramers. As the radius of the nanoparticle increases crowding effects decrease, implying smaller crowding particles have the largest influence on the earliest amyloid species. We explain these results using a theory based on the depletion effect. Finally, we show that spherocylindrical crowders destabilize the ordered $\beta$-sheet dimer to a greater extent than spherical crowders, which underscores the influence of nanoparticle shape on protein aggregation